Electrical activity of oviducts of the rabbit, guinea-pig and human will be recorded using suction electrodes. Data is analyzed to yield frequency of activity and direction and distance of propagation. The effects of hormones and drugs on these parameters will be tested. A computer model of ovum transport using a Monte Carlo method, based on electrophysiological data, will be studied systematically. The cellular control of excitability will be studied using stimulation experiments, by computer analysis of spontaneous activity, through morphological studies of changes in cell junctions and extracellular space, and by studying conduction pathways through circular and longitudinal muscle. BIBLIOGRAPHIC REFERENCES: Hodgson, B.J. and Daly, S. The role of calcium in contraction of the oviduct. In: Harper, M.J.K., Pauerstein, .J., Adams, C.E., Coutinho, E.M., Croxatto, H.B. and Paton D.M. (Eds). Scriptor, Copenhagen, 1976, pp 182-196. Vargas, G.M.I., Talo, A. and Hodgson, B.J. Correlation between intraluminal pressure of the oviduct and the electrical activity of the longitudinal peritoneal muscle of the rabbit. Biol. Reprod. 15, 492-496 (1976).